Spring, 
            
                  April 17, 1990
      
              Arroyo
      
                                        
                                            
                                                                  ,  
            4 vol.
      
                                        
                                                                  , 
            no. 1
      
                                        
                                                                  ,             pages 1-8
      
                                        
                                                                  , 
            8 pp.
      
                                        
                                                                  , 
            Water Resources Research Center
      
                                        
                                                                  , 
            Tucson, AZ
      
                                        
           
       
Although many and varied, all sources of water pollution are classified as either point or nonpoint. Pollution comes from a point source if its origins are distinct and identifiable; hence, point source is also called an end-of-the-pipe source. Pollution from point sources can usually be quantified, often by direct measurement. Point sources can often be regulated effectively with federal and state permits.
